Intramolecular Hydrogen Bond Improved Durability and Kinetics for Zinc-Organic Batteries

Highlights Intramolecular hydrogen bond regulation is proposed to improve the quinone-based polymer (H-PNADBQ) solubility, conductivity, and kinetics. Intramolecular hydrogen bonds reduce molecular polarization and increase π conjugation level, thereby suppressing the dissolution of the H-PNADBQ and accelerating reaction kinetics of H+/Zn2+ uptake/removal. The H-PNADBQ electrodes exhibit excellent durability with high loading of 5 mg cm−2 and 10 mg cm−2, as well as high rate capability (137.1 mAh g−1 at 25 A g−1). Supplementary Information The online version contains supplementary material available at 10.1007/s40820-023-01263-7.


Supplementary Figures
Fig. S1   It can be seen from Fig. S4 that the N-H and C=O groups are located in opposite sites in PNADBQ, so intramolecular HB cannot be formed.Here, PNADBQ was used as a control group to study the effect of intramolecular HB on polymer properties.Of note, the angle between the quinone ring and the naphthalene nucleus of H-PNADBQ molecule is lower than that of PNADBQ, suggesting a increased π-conjugated effect.Of note, the values in Fig. S6 refer to the minimum ESP values on the C=O groups.As we know, the interaction strength between organic compounds and water molecules reflects the solubility of organic materials in water.The negative electron centers of organic materials can interact with H in water molecules.The more negative ESP of organic materials causes a stronger interaction with water, thereby promoting their dissolution.In this work, the C=O groups in H-PNADBQ show higher ESP than that in BQ and PNADBQ compounds, implying reduced solubility of H-PNADBQ due to the formation of intramolecular HB.S3] Both two factors may cause the batteries easily short out.where i is the peak current (mA), and v is the scan rate (mV s -1 ).The b values can be fitted by a linear relationship of log(i) = blog(v) + log(a).
The ratio of capacitance contribution and diffusion contribution is calculated according to equations ( S3) and ( S4): [S5] where  1  refers to the current part contributed by capacitance, and  2  1 2 refers to the current part contributed by diffusion.Note to Figure S21: The H + -storage ability of H-PNADBQ was verified using 0.05 M H2SO4 electrolyte (pH=1) (Fig. S21).A three-electrode system with Ag/AgCl reference electrode, Pt counter electrode, and H-PNADBQ work electrode is fabricated.As shown in Fig. S21a, the shapes of the CV curves of the two electrolytes are almost the same.And a voltage shift of about 0.74 V is detected (Fig. S21b, 0.73 V vs. Zn 2+ /Zn vs. -0.01V vs. Ag/AgCl), which is caused by the H + concentration.Further, the voltage shift is corrected to 0.21 V based on the standard hydrogen electrode (SHE).According to the Nernst Equation, the calculated theoretical voltage shift is 0.22 V, which is close to the experimental value.This result suggests that the redox reaction participated by H + exists in the whole electrochemical process of the H-PNADBQ electrode.The discharge capacity of the battery in 0.05 M H2SO4 electrolyte is 143.8 mAh g -1 , indicating that H-PNADBQ can store H + .

Calculation of potential difference based on Nernst Equation
The electrochemical reaction process of H-PNADBQ electrode in H2SO4 electrolyte can be expressed as below: Corresponding Nernst Equation: Where φ is electrode potential; φ θ is the standard potential; R is the ideal gas constant: 8.314 J K -1 mol -1 ; T is the temperature: 298.15 K; n is the electron transfer numbers; F is the Faraday constant: 96500 C mol -1 .The activity of solid H-PNADBQ and H-PNADBQ-Hn is considered as 1, thus the equation can be further simplified as: The pH value of 2 M Zn(CF3SO3)2 electrolyte is about 4.7.The pH of 0.05M H2SO4 solution is about 1.Therefore, the potential difference bbetween the two electrolytes can be calculated as: Note to Figure S22: 0.1 M Zn(CF3SO3)2 was dissolved into an acetonitrile (ACN) solution to verify the Zn 2+ -storage ability of H-PNADBQ (Fig. S22).As shown in Fig. S22a, a pair of redox peaks in the high voltage range can be detected (O1 and R1) in the 0.1 M Zn(CF3SO3)2/ACN electrolyte.The peaks for O2 and R2 are weak, possibly due to the restricted kinetics.The CV curves of the different electrolytes were similar in shape, and the increased voltage polarization in the 0.1 M Zn(CF3SO3)2/ACN electrolyte could be attributed to the lower ionic conductivity.Thus, the battery in the 0.1 M Zn(CF3SO3)2/ACN electrolyte shows a lower discharge plateau compared to the 2 M Zn(CF3SO3)2 electrolyte (Fig. S22b).A high discharge capacity of 142.6 mAh g -1 is obtained in 0.1 M Zn(CF3SO3)2/ACN electrolyte, indicating that H-PNADBQ has a good ability to store Zn 2+ .

Fig. S7
Fig. S7 LUMO and HOMO plots for different molecules

Fig.
Fig. S8 a) UV-vis spectra of BQ and H-PNADBQ after standing in different solvents for 72 h.b) Optical photographs of these solutions after immersion Note to Figure S8: It can be seen from Fig. S8 that BQ has an obvious absorption peak around 290 nm, and the solution is yellow, indicating that BQ has undergone violent dissolution.While no absorption peak is detected for H-PNADBQ and the solution still keeps clear, confirming the decreased solubility due to the existence of intramolecular HB.

Fig.
Fig. S21 a) CV curves of H-PNADBQ at different electrolytes.b) Charge-discharge curves of H-PNADBQ in different electrolytes (500 mA g -1 )

Fig.
Fig. S22 a) CV curves of H-PNADBQ in different electrolytes.b) Charge-discharge curves of H-PNADBQ in different electrolytes (500 mA g -1 )

Fig.
Fig. S23 a, b) EDS spectra and the elemental contents of by-products in the discharged state

Fig. S25
Fig. S25 XPS pattern of Zn 2p tested at different states